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clint_s152nv

Keep VCT or replace cams?

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Hey guyz

 

Atm im a bit unsure whether or not to replace my annoying sounding VCT or to upgrade the cams to HKS stage 1's or sumthing similar. I dont want full on racing cams so that my car to idles like crazy nor do I want zero fuel efficiency. It's my everyday car so I want sumthing driveable. What are the pros and cons of each?

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personally id say keep the VCT, Good for everyday use and colder type starts and fuel economy and personally there nicer and cleaner to drive :) IMO

Edited by Mr Ron

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Its not necessary to replace the camshafts as it is the helical gear in the VTC which is making the noise. You can either replace the VTC unit which as you said is expensive and will wear again, or you can replace the unit with a solid or adjustable sprocket. Some of the sponsors have adjustable cam gears at a pretty good price. The downside to this option is that you no longer have variable cam timing which you will notice a tiny bit. You lose some low down and midrange response, but no longer have that annoying noise. I have heard of the VTC unit being taken apart and repaired, something to do with the o-rings?? but have never spoken to anyone first hand about it.

 

i replaced the vtc in my car with an adjustable gear and i found after a week or so i was more glad to be rid of the noise and had forgotten the difference that the vtc actually made

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My opinion is to remove the VCT and put some adjustables in..

 

1) If you fix up the VCT the rattle will come back..

2) Adjustables gave you more tuning options and no rattle..

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Im in exactly the same boat, Im replacing the VCT unit.

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^ good choice. i went to tomei adjustable cam gears to get rid of VCT rattle and my car went like absolute shit afterwards.

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If you like the current characteristics and drive-ability of the low down and midrange torque then replace the vtc - yes some will try to tell you that you can get it back with the adjustable cam gears but then you will sacrifice gains you would have made in the top end to gain back what you lost in the low end - the general rule is you can't gain in one without sacrificing from somewhere else

 

VTC is the only way to have the best of both worlds - great low and midrange torque then it switches off for better flow in the top end

 

the chances of you having to replace it again are slim to none (only buy a NEW unit - not second hand/reconditioned)

 

My 97 S14 has this very same issue and has been getting progressively worse over the last year … but still that’s 8-9 years of the factory unit doing it job without much of a problem and now Im looking at having to replace it ….. now in reality what are the chance even if it does give up the ghost in another 8-9 years that most of you will still have the same car (I would even hazard a guess and say that over 90% of you would have sold, crashed/written off or had it repossessed long before the NEW Unit craps itself again.

 

 

Just my 2 cents

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Apex - all depends how much power you're running.. more power is gonna wear that vct alot quicker. If its a stock setup, sure it'll last for years.. if you're running 250rwkw+ forget it, its going to die.

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as others have said, it depends on what you are planning for the car..if it is going to be kept relatively stock then it is worth replacing the vtc unit, but if you are going to be changing camshafts and springs down the track i would go with an adjustable cam gear as the more aggressive cams and stronger springs will wear the new vtc fairly quick bringing back the tractor noise

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as others have said, it depends on what you are planning for the car..if it is going to be kept relatively stock then it is worth replacing the vtc unit, but if you are going to be changing camshafts and springs down the track i would go with an adjustable cam gear as the more aggressive cams and stronger springs will wear the new vtc fairly quick bringing back the tractor noise

 

 

The car currently has 202rwkw from your typical bolt ons and I havent touched the internals apart from injectors. I'm happy with the speed of the car as it is now tho, its at 80000km atm and I plan to keep it for a while since I just bought it. The only time I'm gonna make additions to the engine is if i keep it long enough to see the days of a rebuild. Everyone seems to favor the VCT so I might just keep that! keep the responses comin

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yeh i had the same thing and gotta second hand vct cam gear from someone on here bout a year ago and ive had no problems

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I just replaced my VCT with a new one from nissan.. best 600 bucks i ever spent.. that noise was driving me crazy..

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Apex - all depends how much power you're running.. more power is gonna wear that vct alot quicker. If its a stock setup, sure it'll last for years.. if you're running 250rwkw+ forget it, its going to die.

 

well......

 

I agree that increased lift/duration may contribute to the issue but as it has been suggested in previous threads regarding the same topic its more likely to be the increased pressure stronger springs place on the unit that leads to premature wear/failure however this is still speculation .... Know body knows for sure and can say 100% 'XYZ' Killed my VTC. I say this because most ppl opt for either the adjustable cam gear or they replace it with a second hand/recondition unit which inevitably fails, usually within a year. IMO If you replaced the unit with a Brand new one (as well as cleaned/soaked all the crap out of the squirter's/oil feeds which also undoubtedly contributes to the premature failure) you could happily get 5-10 years performance out of it especially if you are anally pedantic ****or religious if you prefer** about changing your oil/filters/etc every 5,000 kays

 

once again this is all speculation - alot of ppl make the assumptions like too much power and/or cams with anything over 10.5mm lift or 256 duration Kills the vtc therefore it is generally said (often stated as bible) anything outside of these factors and you need to remove the vtc gear and go some adjustable cam gears as it kills the unit anyway - this is generally because cams like hks step 1's, poncams and easy cams all state you can retain the vtc unit as they are straight drop-in, no upgraded springs required - (this IMO doesn't just imply that it due to the lift vs duration but points more to the argument that its the extra load put on the unit by the bigger/stronger springs that kills it (and before anyone starts the whole 'poncams vs stock coil bind debate....' yes I'm aware of the debate but its just an example... :lol: if you prefer..... forget i ever said PONcams and straight drop-in... :ph34r: Jk )

 

so from this I know ppl make 260rwkw+ with step 1's so a blanket statement that says anything over 250rwkw will wear/kill your vtc unit quicker cannot be 100% proved to be true......as I've mentioned there are so many different factor that contribute to its failure ..... just like when an engine fails because the rings went .... it might be that the rings on #3 piston finally gave up the ghost but there would obviously many different factors involved with that (fuel pump missed a beat one too many time or the injector was blocked momentarily causing it to run lean on the #3 pistion causing extra wear on the ring... blah blah blah ... I think you get the point .... its all about contributing factors)

 

I guess in the end everyone needs to make up their own minds (which seems very rare) as to whether they believe all the stories and go with what the majority say or they actually sit and think 'what best suits me..... what best suits my driving style ......etc)

 

 

 

note: My comments are aimed at street driven cars (the daily drivers more than anything) I'm obviously all for keeping the vtc and retaining my torquee 2lt characteristics and having fun every time i exit a round-a-bout and corner. I also like the fact that I'm not having to break every speed limit just to get my turbo to come on boost.... lol

 

That said TRACK cars and Weekend car are a COMPLETELY different story again..... hahahahahaaaa

 

 

 

as others have said, it depends on what you are planning for the car..if it is going to be kept relatively stock then it is worth replacing the vtc unit, but if you are going to be changing camshafts and springs down the track i would go with an adjustable cam gear as the more aggressive cams and stronger springs will wear the new vtc fairly quick bringing back the tractor noise

 

 

The car currently has 202rwkw from your typical bolt ons and I havent touched the internals apart from injectors. I'm happy with the speed of the car as it is now tho, its at 90000km atm and I plan to keep it for a while since I just bought it. The only time I'm gonna make additions to the engine is in a few years when it requires a rebuild but until then I have other plans for it. Everyone seems to favor the VCT so I might just keep that! keep the responses comin

 

 

Man the only thing i can suggest **apart from my own personal opinion*** is that you need to hit the search function like a fiend and do some research so you can make an informed decision not just because a few ppl favour them more than others ...... this is the best place to go ****and you'll find heaps of info regarding this topic especially since its cover every other week**** here it is click me :P Jk

 

 

Good luck with the VTC decision

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Im just about to replace my vct with tomei adjustable cam gears in my s14. I didn't want to pay $600 and i wanted to get rid of that freakin tractor noise as fast as possible that is my reasoning haha.

good luck

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Keep the VCT, adjustable cam gears will never get you the response and mid range power you have with VCT

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In the same position here, running a 2871r + poncams + springs and replacinging with a new VCT unit, will let you guys know in about 5 years hopefully when it goes again!

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im going to modify a brand new vtc for my new engine

 

ill be modifying the outer casing to accommodate a vernier style gearing so i can play around with adjustments, also be modifying the center gear set and trying to smooth out or round off the sharp edges of the split gears and then getting the whole unit cryogenically treated.

Was also thinking of using different size shims behind the spring so that it will not rotate 20deg and more like 10-15deg and play with some more solid adjustments on the vernier

ill be doing all this on an engine dyno so can relaly have a good play with it, but hoping to get some unseen results from it all.

Just a long way away thats all

 

but should do the trick

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apex - agreed, but all of those factors you mentioned are already present, in any engine.. the point is naturally all components are placed under more load/pressure when there is more power and torque present, so its a natural assumption that problem area's, like vct units would wear faster - depending on how you drive of course.

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apex - agreed, but all of those factors you mentioned are already present, in any engine.. the point is naturally all components are placed under more load/pressure when there is more power and torque present, so its a natural assumption that problem area's, like vct units would wear faster - depending on how you drive of course.

 

disenter - yeah very true I guess Im not really disagreeing with you, rather just adding another thought pattern to the equation .......(as I said I still reckon IMO, even with 250-270kw I could get my new VTC unit to last at least another 5-6years before it starts playing up again .... once again this is only my opinion and cannot be 100% proven true like other ppls theories as most of these engines aren't even old enough to have worn through the factory plue another new unit... lol and if it only costs me another $450-600 every 5-7years to keep my 2lt torquee characteristics then I'll gladly pay it but once again that's because it suits my driving style better and therefore makes the car more enjoyable to drive day-to-day. Also I'm lucky in the fact that i have been in another S14 with a similar setup to mine except for adjustable cam gears and it felt noticeably doughier (wait is that even a word ..... dough-ee-er.... lol) down low and not as strong/responsive in the lower part of the midrange.....) and that really cemented it for me

 

 

Anyway was just some food for thought ... I always like hearing other ppls take on things like this :goodevil: its good for self growth hahahahahaaaa :thumbsup:

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